Burners



R. D. COREY Aug. 11, 1964 BURNERS 2 Sheets-Sheet 1 Filed Feb. 28, 1961FIG.

FIG.2

FIG.5

INVENTOR.

RONALD D. COREY FIG.8

ATTORNEY FIGS R. D. COREY Aug. 11, 1964 BURNERS ,2 Sheets-Sheet 2 FiledFeb. 28 1961 FIG. 10

FIG. 11

FIG. 12

United States Patent 3,144,073 BURNERS Ronald Corey, RD. 1, Box 293,Cortland, N.Y. Filed Feb. 28, 1961, Ser. No. 92,308 7 Claims. (Cl.158-7) This invention relates to devices for burning fluid combustiblemixtures, and especially to burners and burner grids for use in suchservice.

In the operation of fluid fuel burners which consume fluid mixtures,such as a mixture of gaseous fuel and an oxygenous gas, noisy operation,roaring and whistling are produced which are annoying and undesirable.Such noises are encountered in many conventional burners which areequipped with a burner grid comprising parallel strips spaced apart toprovide apertures through which the combustible mixture is projected andin front of which the combustion takes place. Such burners are generallyregarded as those of the Bunsen type. The noises are more conspicuous ininstallations where the combustion is forced or where the fuel is usedin relatively large quanity in proportion to the burner orifice, such asa burner system in which the combustion chamher is maintained duringcombustion at pressures below that of the surrounding atmosphere, or ingeneral where the pressure drop across the burner grid is relativelyarge.

A burner construction has now been discovered which does not producethese noises when operated in the service referred to. The novel burnergrid provides a relatively large number of small orifices, a relativelylarge orifice area per unit area of grid and a relatively smallnonorifice area. Thus relatively small burner grids are provided whichare capable of handling relatively large quantities of fuel withoutproducing annoying sounds when operated in the service referred to. Onefeature of the novel burner comprises a grid which may be made byflattening a double coil of wire, thereby forming a flat ribbon, andthen using one or more lengths of the ribbon to form a perforate grid,or partition which is secured in place across the burner orifice in themanner that the grid of a Bunsen burner is mounted.

Accordingly one object of the present invention is to provide novelburners which are quiet in operation and have high capacity.

Other objects of the invention will become apparent from the followingdescription which is made with reference to the drawings in which FIG. 1is a side elevational view of a burner arrangement suitable for burningfluid combustible mixtures such as combustible mixtures of natural gasand air in which the combustion chamber is operated at sub-atmosphericpressures,

FIG. 2 is a partial cross sectional schematic view of the burner housingtaken along a median plane parallel to the plane of the drawing of FIG.1,

FIG. 3 is a partial front elevational schematic view of the burner gridsupport and the burner grid, illustrating one form of grid made inaccordance with the invention,

FIG. 4 is an enlarged front elevational view of another form of grid,

FIG. 5 is a front elevational view of a single length of formed ribbonwhich may be used to form a composite grid,

FIG. 6 is a front elevational schematic view of still another form ofcomposite burner grid and a frame within which the grid is assembled,

FIG. 7 is an end elevational view of a frame made in accordance withFIG. 6, and including a broken away portion of the burner wall whereinthe grid may be mounted,

FIG. 8 is a view in perspective of a modified grid mount,

FIG. 9 is a partial enlarged cross sectional schematic view takensimilarly to FIG. 2 which illustrates a manner of mounting a burnergrid, such as that shown in FIG. 8, 7

FIG. 10 is an enlarged side elevational view of a section of the grid,

FIG. 11 is a schematic view partially in elevation and partly in crosssection of a burner having a circular burner grid, and

FIG. 12 is a cross sectional schematic view of the burner shown in FIG.11 taken along the line XIXI.

Referering to FIG. 1 the burner is enclosed within the burner housing 1which is connected by the pipe 2 to a control or mixing device 3 whichsupplies a combustible mixture of fluid combustible and oxygenous gas tothe burner through a fuel mixing chamber 4 (FIG. 2) at the rear of theburner grid 5. Gaseous combustible may be supplied to the mixing devicefrom a source (not shown) through the pipe 6, and air or otheroxygencontaining gas may be supplied to the mixing device through thepipe 7. Combustion takes place in a combustion chamber 8 (FIG. 2) infront of the grid where a means for igniting the combustible mixture,such as the electrical spark plug 9 is disposed. The walls of chamber 4form an extension of the pipe 2 and the burner grid 5 is mounted on asuitably formed facing in the chamber wall 10 and across the burnerorifice. In this case the burner grid is disposed normal to the axis ofthe combustion chamber 8. The burner grids may be shaped in variousways, such as flat, cylindrical, spherical or a section of the surfaceof any conic section to suit the needs of any special condition.

The grids of the present invention may be made by taking a double coiledwire which is a composite of two intermeshed coils, and crushing it intoa fiat ribbon while urging the crushing force endwise in the directionof the axis of the coil, so that the coils will lay over each other whenflattened. Then the ribbon is cut into suitable lengths. While only onelength of the ribbon may in certain cases be used as the burner grid,other forms may be made by placing the lengths of ribbon side by sidecontiguously and with the ends even. One form of grid may be made byfastening the lengths together along their contiguous margins by anysuitable means, as by welding or by lacing with a fine wire. Solderingmay also be employed but welding, such as the welds 12 (FIG. 4) is adesirable means. The composite grid thus formed is self sustaining andmay be sprung into a channel 15 (FIGS. 3 and 5) which is rabbeted intothe margin of the burner orifice. A pair of stiffeners, such as wires 11(FIGS. 2 and 3) may desirably be mounted across the mid-portion of thegrid, in front and in back, and extended through opposite margins of theorifice. These stiffeners serve also to hold the grid in place.

Another form of composite grid is shown in FIG. 3 in which the lengths14 of the flattened ribbon, such as that shown in FIG. 5 are sprung intothe groove 15 so that the ends will be firmly engaged. In thismodification the side margins of the ribbons may not necessarily befastened together, provided the strips are contiguous to one another andfill the entire orifice, or in case filler strips 16 are mounted in thegrooves, preferably one on each side of the grid element, so that theburner grid will be symmetrically placed in the burner housing. Thisarrangement is especially useful in that the area of the grid may beeasily changed at will.

The burner grid illustrated in FIG. 6 comprises an internally grooved orchanneled frame 20 for holding the lengths of ribbon. The frame 20 maydesirably be formed from short lengths of channel and fastened at thecorners, as by welding. Another arrangement is shown in FIG. 6 whereinthe upper and lower channel members are left open at one end, and stops,such as the pins 21 are passed from front to back through the oppositesides of the channel members to hold the burner grid-forming parts insecure alignment and in place. Instead of the pins 21, the open ends ofthe channels may be bent inwardly to engage the end grid. This structurewith its frame constitutes a unit which may be mounted across the burnerorifice in a groove 15 which may be open at one end so that the framedunit may be readily removed and replaced. When the framed unit isremoved the grid area may be readily altered or repaired. When pins 21are used to retain the grid elements in the frame, the open ends ofeither or both channels may be sprung outwardly toengage the sides ofthe groove 15 for lodging the framed grid therein, but other means maybe used.

FIG. 8 is illustrative of another modification in which any of the gridforms may be mounted in a frame 20, such as that shown in FIGS. 6, 8 and9. The modification shown in FIGS. 8 and 9 is a rectangular channeledframe in which the grid elements are mounted, either individually or asa composite or unitary grid. Tabs 30 extending obliquely and outwardlyfrom the plane of the outer side of the frame may be cut out of the wallof the channel. The burner orifice is then formed to fit the frame 2 andan inwardly projecting flange 31 on the inner side of the Wall it isprovided to serve as a seating member upon which to seat the framed gridelement. The framed grid is then pressed into the burner orifice untilit is seated and the tabs are sprung inwardly so that the tabs terminaledges press against the inner margins of the orifice, holding the unitsecurely in place. Instead of cut-outs the tabs 30 may be strips ofmetal, or other projecting members on the frame which may be sprunginwardly toward each other when the frame is seated. The frame shown inFIG. 6 may be similarly provided with tabs or cut-outs. If desiredsuitable depressions, channels or notches may be formed in the orificefor engaging the outer ends of the members 30.

A grid of heat resistant material comprising a plurality of thedescribed perforate strips or ribbons mounted contiguously along theirsides forms a grid in which all the openings in the grid have curvedsides. The openings 26 distributed lengthwise along the middle area ofeach ribbon in regular pattern are the largest, and the margins of theseopenings as viewed from within the same are concavo-concave, which is tosay that they curve away from each other in the manner that a pair ofparentheses curve. At the ends or points of the concavo-concave shapedmargins are three sided openings 27 having three concave sides asreferred to the longitudinal axis of the ribbon, one of which sidesbulges outwardly from the axis, and two of which form a point directedtoward and transversely to the axis of the ribbon. The latter two sidesare in line with the points of the concavo-concave margins. Above andbelow each pointed end of the concavo-concave openings on both sides ofthe ribbon are four sided openings 23, having two meeting concave sidesdirected toward and transversely to the longitudinal axis of the ribbon,and two meeting concave sides meeting in a point directed away from saidaxis. The latter sides bulge outwardly near the margins of the ribbon.All these openings are arranged in a regular repetitive pattern whichmay be formed when the double coil of wire is crushed into a flat ribbonin which the coils lay over and upon each other in the manner heretoforedescribed.

While the invention has been illustrated hereinbefore with referenceprincipally to flat grids, curved grids may be conveniently provided bysuitably curving the walls 10 which support the grid and forming in thedesired manner the channels within which the grids are lodged.

This wall and channeled structure may be elongated so that the wall 10is cylindrical and the channels are circular. When the grid iscylindrical it may be formed by fastening the ends of one or more stripsof ribbon together to form a cylinder. When a plurality of ribbons arethus formed into a cylinder the sides may be securely fastened togetheralong their touching longitudinal edges. For mounting a cylindricalgrid, a chamber 4 having cylindrical walls 10 may be provided, said wallbeing flanged at the end to provide a circular wall 10a. In the circularwall 10a a circular retaining channel 15 is formed, in which the upperlongitudinal margin of the grid or ribbon is disposed. The otherlongitudinal margin of the ribbon or grid is disposed in a circularchannel formed near the edge of a circular disc or cap 1017 which may bespaced from the flanged end of the cylindrical wall 4 to form an orificeabout the Width of the cylindrical grid. The disc and grid may be heldin position by a centrally disposed bolt 20 which is threaded into a web21 which is supported within the chamber 4 and which is attached to theinner surface of the wall 10.

Burner grids made to conform to the structures described are perfectlyquiet in operation and are capable of handling extraordinarily largevolumes of combustible per unit of grid area. The grids may be easilyand economically made by flattening coils of heat resistant wire in themanner described, but other methods of making such perforate grids maybe employed. Any kind of heat resistant wire which may be worked in themanner described may be used. Wire of about 0.030 to about 0.040 inch indiameter, formed into a double coil about one half inch in diameter is asatisfactory proportion for making a medium sized ribbon, but larger orsmaller wire, or larger or smaller coils may be successfully used as thestarting structure. Wire having circular cross section is satisfactory,but other cross sectional shapes may be used.

From the foregoing disclosure it will be recognized that the inventionis susceptible of still other modifications without departing from thescope and spirit thereof, and it is to be understood that the inventionis not restricted to the specific illustrations herein set forth, exceptin so far as they are specifically limited by the terms of the appendedclaims.

This is a continuation-in-part of my application serial No. 831,327,filed Aug. 3, 1959, now Patent No. 3,115,- 302.

I claim:

1. A burner assembly comprising a burner housing having a combustionchamber and a fuel mixing chamber therein; a partition between saidchambers having a burner orifice therein; a perforate burner griddisposed across said orifice; said mixing chamber conducting a supply offluid combustible mixture to said grid; means for marginally securingsaid grid in place for partitioning said combustion chamber from saidfuel mixing chamber; said grid comprising a perforate ribbon of heatresistant material formed by flattening two interlaced wire coils; saidribbon having openings distributed lengthwise along its middle area inregular pattern, the margins of said openings being concave-concave andthe axis through the pointed ends thereof being disposed transverse tothe longitudinal axis of the ribbon; openings at the pointed ends ofsaid margins which have three sided margins, two sides of which areconvex and meet in a point directed transversely to said longitudinalaxis and in line with the points of said concavo-concave margins, thethird side of said three sided openings being convex and bulging awayfrom said axis; and a plurality of four sided openings above and beloweach point of the margins of said concavo-concave openings, said foursided openings having two meeting concave margins bulging outwardly fromsaid longitudinal axis and two convex margins forming a point which isdirected inwardly and transverse to said longitudinal axis, all of saidopenings being arranged in a regular repetitive pattern throughout thelength of said ribbon.

2. A device in accordance with claim 1 in which the burner gridcomprises a plurality of said ribbons assembled contiguously side byside.

3. A device in accordance with claim 1 in which the burner gridcomprises a plurality of said ribbons assembled contiguously side byside; and means for securing the ribbons in place.

4. A device in accordance with claim 1 which comprises a plurality ofsaid ribbons assembled contiguously side by side; and means forfastening said contiguous sides together.

5. A device in accordance with claim 1 in which the burner gridcomprises a plurality of ribbons assembled side by side; said means formarginally securing said grid in place, a channeled frame in which thechannel opens inwardly, said ribbons being assembled with their endsdisposed in said channeled frame.

6. A device in accordance with claim 5 in which the frame is mountedwithin said burner orifice; and means for securing the frame in place.

7. A device in accordance with claim 1 in which the grid is cylindricaland is secured in place by clamping opposite longitudinal sides thereofin circular grooves, one of said grooves being formed in the chamberwall and the other being formed near the edge of a circular disc whichis spaced from the wall of the chamber.

References Cited in the file of this patent UNITED STATES PATENTS731,384 Newbold June 16, 1903 2,336,816 Thompson Dec. 14, 1943 2,435,391Gunderman Feb. 3, 1948 2,644,946 Menz et al. July 14, 1953

1. A BURNER ASSEMBLY COMPRISING A BURNER HOUSING HAVING A COMBUSTIONCHAMBER AND A FUEL MIXING CHAMBER THEREIN; A PARTITION BETWEEN SAIDCHAMBERS HAVING A BURNER ORIFICE THEREIN; A PERFORATE BURNER GRIDDISPOSED ACROSS SAID ORIFICE; SAID MIXING CHAMBER CONDUCTING A SUPPLY OFFLUID COMBUSTIBLE MIXTURE TO SAID GRID; MEANS FOR MARGINALLY SECURINGSAID GRID IN PLACE FOR PARTITIONING SAID COMBUSTION CHAMBER FROM SAIDFUEL MIXING CHAMBER; SAID GRID COMPRISING A PERFORATE RIBBON OF HEATRESISTANT MATERIAL FORMED BY FLATTENING TWO INTERLACED WIRE COILS; SAIDRIBBON HAVING OPENINGS DISTRIBUTED LENGTHWISE ALONG ITS MIDDLE AREA INREGULAR PATTERN, THE MARGINS OF SAID OPENINGS BEING CONCAVO-CONCAVE ANDTHE AXIS THROUGH THE POINTED ENDS THEREOF BEING DISPOSED TRANSVERSE TOTHE LONGITUDINAL AXIS OF THE RIBBON; OPENINGS AT THE POINTED ENDS OFSAID MARGINS WHICH HAVE THREE SIDED MARGINS, TWO SIDES OF WHICH ARECONVEX AND MEET IN A POINT DIRECTED TRANSVERSELY TO SAID LONGITUDINALAXIS AND IN LINE WITH THE POINTS OF SAID CONCAVO-CONCAVE MARGINS, THETHIRD SIDE OF SAID THREE SIDED OPENINGS BEING CONVEX AND BULGING AWAYFROM SAID AXIS; AND A PLURALITY OF FOUR SIDED OPENINGS ABOVE AND BELOWEACH POINT OF THE MARGINS OF SAID CONCAVO-CONCAVE OPENINGS, SAID FOURSIDED OPENINGS HAVING TWO MEETING CONCAVE MARGINS BULGING OUTWARDLY FROMSAID LONGITUDINAL AXIS AND TWO CONVEX MARGINS FORMING A POINT WHICH ISDIRECTED INWARDLY AND TRANSVERSE TO SAID LONGITUDINAL AXIS, ALL OF SAIDOPENINGS BEING ARRANGED IN A REGULAR REPETITIVE PATTERN THROUGHOUT THELENGTH OF SAID RIBBON.